The present invention relates to a tray feeder supplying electronic parts packed in a tray to a part-mounting-apparatus and a method of picking up parts from the tray.
In a part-mounting-apparatus, a method of using tray feeders is known as one of the methods of supplying electronic parts, e.g., semiconductor chips. In this tray feeder, a plurality of parts are packed in a planar condition in these trays, and the trays are accommodated in a container such as a magazine. Respective trays are sequentially taken out according to the order of parts to be supplied, and the parts are supplied to a pick-up point where a pick-up head of the apparatus picks up the parts.
In one of conventional magazines, trays are accommodated in a vertical direction and a tray is drawn horizontally by a drawing section, and the drawing section is elevated or lowered to a pick-up point. When the drawing section have moved and the tray halts at the pick-up point, a pick-up head moves from a stand-by position to pick up a part from the tray. In other words, at every pick-up action, the head lowers from the stand-by position to the pick-up point and picks up the part by bringing a nozzle of the head in contact with an upper surface of the part contained in the tray. As such, a conventional tray feeder requires the head, at every pick-up action, to move from the stand-by position to the pick-up point. This results in increasing a cycle time of part-mounting.
Further, in the conventional tray feeder discussed above, the tray rises to the pick-up point, and subsequently the head starts lowering regardless of types of the parts. Thus a time for lowering the head varies depending on a thickness of a part, i.e., the head must lowered additionally in the case of a thin part. In this case, it takes a longer time, which increases the cycle time of the part-mounting.
The present invention addresses the problem discussed above, and aims to provide a tray feeder, which can improve productivity by shortening a cycle time of part-mounting, and a method of picking up parts using the tray feeder.
The tray feeder of the present invention supplies parts to a pick-up point where a head of a parts-mounting-apparatus picks up the part, and the tray feeder comprises the following elements:
(a) a drawing section for drawing a palettexe2x80x94holding a tray in which parts are packedxe2x80x94from a container accommodating the palette, and holding the palette;
(b) a lift for elevating or lowering the drawing section;
(c) a controller for controlling the head to start lowering before the palette drawn reaches a pick-up point;
Another tray feeder of the present invention comprises the following elements:
(a) a drawing section for drawing a palettexe2x80x94holding a tray in which parts are packedxe2x80x94from a container accommodating the palette, and holding the palette;
(b) a lift for elevating or lowering the drawing section;
(c) a timing setter for setting a timingxe2x80x94for a pick-up head to start lowering from a stand-by positionxe2x80x94in relation to a height of the drawing section and responsive to types of the parts packed in the palette; and
(d) a controller for controlling the head to start lowering from the stand-by position when the drawing section reaches the height set in relation to the timing.
A method of picking up parts from a tray according to the present invention comprises the following steps:
(a) drawing a palettexe2x80x94holding a tray in which parts are packedxe2x80x94from a container by a drawing section which can be elevated or lowered, and then holding the palette;
(b) controlling a pick-up head of a parts-mounting-apparatus to start lowering before the palette drawn by the drawing section reaches a pick-up point; and
(c) picking up a part from the pick-up point by the head after the palette reaches the pick-up point.
Another method of picking up the parts comprises the following steps:
(a) drawing a palettexe2x80x94holding a tray in which parts are packedxe2x80x94from a container by a drawing section which can be elevated or lowered, and then holding the palette;
(b) starting to lower the head when the drawing section reaches the height set in relation to a timing of the head starting to lower and responsive to types of parts packed in the palette, in a course of the drawing section, which draws and holds the palette, rising toward a pick-up point; and
(c) picking up a part from the pick-up point by the head after the palette reaches the pick-up point.
According to the present invention, before the palette held by the drawing section arrives at the pick-up point, the pick-up head starts lowering from the stand-by position, thereby reducing a time for picking a part up. Further, before the drawing section arrives at the height of pick-up point, the head starts lowering from the stand-by position with a timing set responsive to types of the parts. This mechanism also reduces a time for picking a part up, and as a result, the total time for part-mounting can be reduced.